Re: Structural v. semantic markup

Nick Arnett (
Wed, 2 Nov 1994 09:27:02 -0800

At 5:57 PM 11/1/94, Mike Piff wrote:

>Do you mean that <section> is structural, but <theorem>, <proof>,
><implies>, <xor> are semantic? Or are only the last two symbol place-
>holders semantic?

It's not an either/or question, which I didn't make clear. Sorry.

Relationships, such as "is a" or "relates closely to," between words or
phrases are lexical. Semantics takes into account not only those lexical
relationships, but also grammar and other structure, including the semiotic
information communicated by layout, fonts, etc. So "semantic markup"
implicitly should include structural and lexical tags.

In other words, I should have said earlier that you can't have semantic
markup without a lexical tagging scheme in addition to structural tagging.

Using a tag like <theorem> in a document would seem to cross the fence
between the two, I think, which probably isn't a good thing. What you seem
to be suggesting is that you'd use this tag when there's an element of a
document which "is a" theorem, a lexical relationship. So how would you
use it? Writing something like this doesn't seem like a good idea:

<theorem>Yadda, yadda, yadda</theorem>

Instead, tagging along the following lines is much richer and flexible,
since it can express relationships that are ambiguous or inexpressible in
flat or relational models.

Yadda, yadda, yadda<LEX element="paragraph", relationship="is a",

I have no idea if LEX is the right name, etc. Forgive me if I don't dig
too deeply into the implementation issues -- I'm quite aware of my own
ignorance in that regard. I know that I'd like to see this sort of thing
supported; I'm hoping that some real expertise in this domain enters into
the HTML development efforts.